Vol. 11, Special Issue 7 (2022)

Author(s):
Pradeep Godwal, Meenaxi Sareen, Amit Kumar Chotiya, NS Rathore, Anil Moolchandani, RA Legha, Yash Pal and Vijay Kumar

Abstract:
The effect of heat stress on the diurnal rhythmic changes in physiological indices was studied in Martina Franca donkeys (n=6) in the semitropical arid desert climate in the two periods i.e, i) ‘High THI (Thermal heat index) period in October 2016 with solar exposure form 10.00 h to 14.00h in the afternoon and ii) ‘Thermoneutral THI period’ in winter (28 Dec, 2016) under same period of solar exposure in open sheds. Physiological responses were recorded at 0.700h, 10.00h, 14.00h &16.00h for 7 consecutive days in the heat stress period which were compared with that on one single day in winter. All physiological responses respiration rate (RR), rectal temperature (RT), heart rate (HR), skin temperature (ST) increased significantly due to heat stress in the afternoon than in the morning hours during October 2016 in heat stress climate of high thermal heat index (THI). Overall, the study concluded that the impact of climatic heat stress due to solar radiation in the afternoons in exotic Martina Franca donkeys was significant in terms of increased physiological stress indices. The impact showed diurnal rhythmicity which whose magnitude reduced with the decline in climatic THI with the diurnal time point in day and season.z